C-PSP

Purification, characterization and developmental expression of chick (Gallus domesticus) liver PSP protein.
Nordin H, Matsumoto M, Suzuki K, Kaneki K, Natori Y, Kishi K, Oka T.

Department of Nutrition, School of Medicine, University of Tokushima, 770-8503, Tokushima, Japan.
We have isolated a perchloric acid-soluble protein designated as C-PSP from the post-mitochondria supernatant fraction of chick liver. It is soluble in 5% perchloric acid and purified by ammonium sulfate, fractionation and CM-Sephadex chromatography. The C-PSP showed approximately 70% homology with PSP isolated from rat liver (L-PSP1) with its partial amino acid sequences. The protein has a molecular mass of approximately 14 kDa which was slightly higher than that of L-PSP1. It inhibited protein synthesis in a rabbit reticulocyte lysate system. C-PSP was mainly expressed in liver and kidney and was also expressed in intestine, gizzard, glandular stomach, heart, brain and spleen though its expression was low. The expression of C-PSP in liver increased gradually from the 1st day to the 2nd week and it remained almost the same until the 13th week. C-PSP was also found in day 8 chick embryonic tissues. Interestingly, we found that C-PSP was expressed as a differentiation-dependent manner in the nervous cells of chick embryos. Thus, our findings are the first report on the presence of a PSP in avian tissues which may be involved in the regulation of cellular growth and differentiation.
PMID: 11163312 [PubMed - indexed for MEDLINE]